Polyelectrolyte complexes. II. Specific aspects of the formation of polycation/dye/polyanion complexes

Drăgan, Ecaterina Stela; Drǎgan, Demetra; Cristea, Mariana; Airinei, Anton; Ghimici, Luminiţa

doi:10.1002/(sici)1099-0518(19990215)37:4<409::aid-pola4>3.0.co;2-t

Cited by 39 publications

(32 citation statements)

References 27 publications

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“…NaPAMPS with different molar masses, synthesized and purified as previously described,40 was used as a polyanion. NaPAMPS molar masses were determined by viscometry41 and size exclusion chromatography, and the values are summarized in Table 1.…”

Section: Methodsmentioning

confidence: 99%

“…Interpolyelectrolyte complexes (IPECs) with different structures and properties (stoichiometric1–16 or nonstoichiometric17–28) can result from a very fast, ionic exchange reaction between two oppositely charged polyelectrolytes, accompanied by the release of the corresponding small counterions, leading to the increase of the system entropy and to the complex stability. Nonstoichiometric IPECs (NIPECs) have been obtained mainly when the complementary polyelectrolytes have significantly different molar masses, nonstoichiometric systems and dilute aqueous solutions,3, 4, 18–23 structural differences between oppositely charged polyions, and the presence of low amounts of NaCl being also necessary to obtain soluble NIPECs 18.…”

Section: Introductionmentioning

confidence: 99%

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Polyelectrolyte complexes. VI. Polycation structure, polyanion molar mass, and polyion concentration effects on complex nanoparticles based on poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate)

Drăgan¹,

Schwarz

2004

J. Polym. Sci. A Polym. Chem.

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The formation and characterization of some interpolyelectrolyte complex (IPEC) nanoparticles based on poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate) (NaPAMPS), as a function of the polycation structure, polyanion molar mass, and polyion concentration, were followed in this work. Poly(diallyldimethylammonium chloride) and two polycations (PCs) containing (N,N‐dimethyl‐2‐hydroxypropyleneammonium chloride) units in the backbone (PCA5 and PCA5D1) were used as starting polyions. The complex stoichiometry, (n−/n+)iso, was pointed out by optical density at 500 nm (OD500), polyelectrolyte titration, and dynamic light scattering. IPEC nanoparticle sizes were influenced by the polycation structure and polyanion molar mass only before the complex stoichiometry, which was higher for the more hydrophilic polycations (PCA5 and PCA5D1) and for a higher NaPAMPS molar mass, and were almost independent of these factors after that, at a flow rate of the added polyion of about 0.28 mL × (mL PC)−1 × h−1. The IPEC nanoparticle sizes remained almost constant for more than 2 weeks, both before and after the complex stoichiometry, at low concentrations of polyions. NIPECs as stable colloidal dispersions with positive charges in excess were prepared at a ratio between charges (n−/n+) of 0.7, and their storage colloidal stability, as a function of the polycation structure and polyion concentration (from 0.8 to ca. 7.8 mmol/L), was demonstrated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2495–2505, 2004

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Polyelectrolyte complexes. VI. Polycation structure, polyanion molar mass, and polyion concentration effects on complex nanoparticles based on poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate)

Drăgan¹,

Schwarz

2004

J. Polym. Sci. A Polym. Chem.

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“…However, the reactive oligomers containing preformed QAS groups seem to be proper precursors to obtain cationic‐modified PDMS with QAS in the backbone. The reaction of some aliphatic secondary amines (dimethylamine and diethylamine) with epichlorohydrin (ECH), under strict control of the ECH/amine molar ratio, solvent, and temperature, offered well‐defined reactive cationic oligomers (RCO) containing preformed QAS groups 8, 9…”

Section: Introductionmentioning

confidence: 99%

Hydrophilic coating aids radial sheath withdrawal and reduces patient discomfort following transradial coronary intervention: A randomized double‐blind comparison of coated and uncoated sheaths

Kiemeneij

Fraser

Slagboom

et al. 2003

Cathet Cardio Intervent

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Radial artery spasm may cause severe discomfort during radial artery sheath removal. A hydrophilic-coated sheath may reduce the force required to remove a radial sheath. This force may be quantified using an automatic pullback device (APD). The objective of this study was to assess if a hydrophilic coating reduces the required force and discomfort associated with removal of a radial sheath following transradial coronary intervention. Ninety patients undergoing percutaneous coronary intervention via the radial artery were randomly assigned to two groups receiving either coated or uncoated introducer sheaths. Radifocus Introducer II (Terumo) 25 cm, 6 Fr radial sheaths and sheaths that were identical apart from the presence of the coating were used in all patients. The APD was used for sheath removal at the end of the procedure. Three patients (7%) in the coated group experienced discomfort during automatic sheath removal, compared to 12 patients (27%) in the uncoated group (P = 0.02). The maximum pullback force (MPF) was significantly lower in the coated compared to the uncoated group (0.24 +/- 0.31 vs. 0.44 +/- 0.33 kg; P = 0.003). Similarly, the mean pullback force was significantly lower in the coated group (0.14 +/- 0.23 vs. 0.32 +/- 0.24 kg; P < 0.001). Only one patient (2%) in each group had an MPF greater than 1.0 kg together with clinical evidence of radial artery spasm. Removal of the coated Terumo Radifocus sheath requires less force than an identical uncoated sheath. The coated sheath was also associated with less discomfort for the patient.

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“…30 PAMPS was synthesized and purified as previously published. 31 The copolymer P(AMPS 55 -co-AA 45 ) was synthesized and purified as previously published. 32,33 The overall characteristics of the polyions used in this study are summarized in Table I. HSA with 96-99% purity and phosphate-buffered salt (PBS) purchased from Sigma-Aldrich, Germany, were used without any further purification.…”

Section: Methodsmentioning

confidence: 99%

Composite multilayer thin films morphology and their interactions with proteins as a function of polyanion structure

et al. 2011

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Composite multilayer thin films have been constructed on planar substrates by the layer-by-layer deposition of chitosan (CS) and two strong polyanions different by the density of sulfonic groups, i.e., poly(sodium 2-acrylamido-2-methylpropanesulfonate) (PAMPS) and a random copolymer of AMPS with acrylic acid, P(AMPS 55 -co-AA 45 ); all deposition steps being performed at pH 5.5. The effect of the polyanion structure and number of adsorbed layers on the film morphology was examined by atomic force microscopy and contact angle measurements. The polyanion structure strongly affected the multilayer morphology, more swollen and less dense films being formed when P(AMPS 55 -co-AA 45 ) was used compared to PAMPS. The sorption of two proteins, human serum albumin and bovine serum albumin, on the film surface with CS as the last layer adsorbed, as a function of the polyanion structure, indicates that a higher amount of protein had been sorbed mainly on the film surface when PAMPS was used as a polyanion in the film construction.

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Polyelectrolyte complexes. II. Specific aspects of the formation of polycation/dye/polyanion complexes

Cited by 39 publications

References 27 publications

Polyelectrolyte complexes. VI. Polycation structure, polyanion molar mass, and polyion concentration effects on complex nanoparticles based on poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate)

Polyelectrolyte complexes. VI. Polycation structure, polyanion molar mass, and polyion concentration effects on complex nanoparticles based on poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate)

Hydrophilic coating aids radial sheath withdrawal and reduces patient discomfort following transradial coronary intervention: A randomized double‐blind comparison of coated and uncoated sheaths

Composite multilayer thin films morphology and their interactions with proteins as a function of polyanion structure

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